1. Field of the Invention
The present invention relates to a display substrate. More particularly, the present invention relates to a display substrate used for a flat panel display device.
2. Description of the Related Art
A liquid crystal display (LCD) device, which is a type of display device, generally includes a display substrate, a color filter substrate facing the display substrate and a liquid crystal layer interposed between the display substrate and the color filter substrate.
The display substrate includes a signal line, a thin-film transistor (TFT), a pixel electrode, etc., that are formed on an insulating substrate to independently drive a plurality of pixels. The color filter substrate includes a color filter layer, a common electrode, etc. The color filter layer includes red (R), green (G) and blue (B) color filters, and the common electrode faces the pixel electrode.
When a screen size of the LCD panel is increased, a length of the signal line is increased. Also, when a resolution of the LCD panel is increased, a width of the signal line is decreased. Thus, resistance of the signal line is increased, and intensity of signals transmitted through the signal line is decreased. Also, the signals may be delayed. In order to solve the above-mentioned problems, the signal line includes a low resistance material such as copper.
The signal line including copper may be formed through a damascene process. In the damascene process, a trench is formed on a base substrate, and the copper is plated in the trench. However, a gas that is generated during copper plating may cause the signal line to be lifted off from the base substrate, thereby deteriorating stability of the signal line.